A light wave may be formed of electrical field vectors, i.e. peaks and troughs, radiating out in all directions from the direction of propagation of the light wave. A polarizer may be, in essence, a screen that allows only a narrow segment of the vectors to pass, namely those vectors that are oriented in a specific plane.
A polarizer may be used for beam splitting, combining, polarization, or like-functions, and may be formed of a series of extraordinarily thin conductive “ribbons”, each running parallel to each other of the “ribbons”. This is known as a wire-grid, or grating, polarizer. In an instance wherein radiation, such as visible or infrared light, strikes the wire-grid of the polarizer, some of that radiation is reflected, while that portion of the radiation that is selectively polarized by the wire grid may pass. Such a wire grid polarizer polarizes the radiation wave incident on the parallel conductors perpendicularly to the length of the conductors.
The grid, or grating, of a grid polarizer may be highly dense, due, in part, to the fact that the “ribbons” must be closer together than the wavelength of the radiation to be polarized, controlled, or analyzed. Thus, the smaller the wavelength of the radiation to be operated on is, the more dense the wire grid must be in order to operate on the subject radiation. This has been, as is known in the art, a limitation on the types of radiation that may be polarized using such a polarizer. For example, wire grid polarizers/beam splitters have historically been used in the microwave region, in which longer wavelengths make the construction more feasible.
The polarization of radiation may be used to control the radiation that is the subject of the polarization, such as in a splitter or combiner, and to analyze the polarization characteristics of an object, such as by examining the light reflected from, or by, an object. Polarization characteristics may provide for extraction of significant information about the physical and chemical makeup of an object and of a surface. A polarizing beam splitter may thus act as an analyzer, for example, reflecting unwanted light, and passing desired light.
Exemplary optical and electro-optical polarizer applications may include lasers, glare-reduction, lens coating, display enhancement, and exploitation of limited bandwidth availability, to name a few. For example, through “frequency reuse,” an antenna may simultaneously transmit adjacent beams at the same frequency, and, by polarizing each beam differently, nonetheless maintain useful beam isolation.
In the fields of optics, telecommunications, optical and electro-optical applications and photonics, it may be highly desirable to enhance device performance and reduce fabrication, packaging and assembly costs, such as by providing polarization capabilities that provide improved performance through a broader range of radiation, but that can be fabricated at low cost. For example, it may be desirable to provide a improved photonic component, which may be incorporated into a Photonic Integrated Circuit (PIC), or with another photonic device.
Accordingly, it is desirable to provide a polarization controller, system, device, and method that employs nanostructures to perform polarization, thereby providing improved performance through a broader range of radiation wavelengths at a low fabrication cost.